![]() |
|
Clinical data | |
---|---|
Pregnancy category |
|
Dependence liability |
None |
Routes of administration |
Oral |
ATC code |
|
Legal status | |
Legal status |
|
Pharmacokinetic data | |
Onset of action | about 1 hour |
Biological half-life | 3 hours |
Identifiers | |
|
|
Synonyms | γ-L-glutamylethylamide |
CAS Number | |
PubChem CID | |
ChemSpider | |
UNII | |
KEGG | |
ChEBI | |
ECHA InfoCard | 100.019.436 |
Chemical and physical data | |
Formula | C7H14N2O3 |
Molar mass | 174.19766 g/mol |
3D model (Jmol) | |
Melting point | 174.20 °C (345.56 °F) |
Boiling point | 215 °C (419 °F) |
|
|
|
Theanine /ˈθiːəniːn/, also known as L-γ-glutamylethylamide and N5-ethyl-L-glutamine, is an amino acid analogue of the proteinogenic amino acids L-glutamate and L-glutamine and is found primarily in particular and fungal species. It was discovered as a constituent of green tea in 1949 and in 1950 was isolated from gyokuro leaves, which have high theanine content. Appearance of the name "theanine" without a prefix is understood to imply the L-enantiomer, which is the form found in fresh teas and in some, but not all dietary supplements. The opposite D-enantiomer has far fewer studied pharmacologic properties, but is present in racemic chemical preparations, and substantially in some studied theanine supplements.
In Japan, L-theanine has been approved for use in all foods, including herb teas, soft drinks, desserts, etc., with some restrictions applying to infant foods. It provides a unique brothy or savory (umami) flavor to green tea infusions. As an ingredient, it is generally recognized as safe (GRAS) by the Food and Drug Administration (FDA), and is sold as a dietary supplement in the US. However, the German Federal Institute for Risk Assessment, an agency of their Federal Ministry of Food and Agriculture, has objected to the addition of isolated theanine to beverages.